Henby liepmann



(No Model.)

H. LIEPMANN.

CARBON ELECTRODE FOR ELEGTROLYTIOAL PURPOSES.

No. 330,247; Patgnted Nov. 10, 1885 N. PETERS, Phmo-Lilhv n hen wmin mn,D. C.

To all whom it may concern:

ilNJTED STATES PATENT Carrion.

HENRY LIEPMAnnoF LONDON, COUNTY or MIDDLESEX, ENGLAND.

CARBON ELECTRODE FOR EZL ECT ROLYTICAL. PURPOSES SPECIFICATION formingpart of Letters Piatent No. 330,247, dated November 10, 1885.Application filed July 2 1 1885. Serial No. 172,233. (No tiuodel.)Patented in England February 25, 1884, No, 3,884.

Be it known that I,IIENRY IJIEPMANN,1]12L11- aging director of theLiepmann Carbon Com-E pany, (Limited) Nelson Wharf,Mil1wall,Loni don, inthe county of Midd'lesex, England, chemist, Ph. D., F. O. S., &c., asubject of the Queen of Great Britain, residing at 40; Lexham Gardens,London, in the county of 'Middlesex, England, have invented Improved aspossible the electrolyte or solution sub-l jected to electrolysis, andalso the material l upon which the solution is to act, and it is alsodesirable to have as large a surface as possible. The substance employedin the construction of these electrodes must be of such a nature that itdoes not itself undergo any material electrolytical decomposition, andfor this purpose carbon is generally employed; In the case where thepoles or electrodes,instead of being stationary,are required to beactuated,so as to keep in motion the electrolyte and the material orsubstance to be acted upon, it is necessary that their size and strengthbe increased sufficiently to enable them to bear the strain to whichthey are subjected. The manufacture of carbon in one piece which shallhave the necessary uniform density, homogeneousness of material, andstrength throughout beyond a certain size and thickness presents,however, considerable difficulties.

The object of my invention is to devise means by which these essentialqualities of size, combined with uniform strength, homogeneousness ofmaterial, and density shall be produced in the electrodes without thenecessity of manufacturing them in one continuous piece or block, andalso to give them at the same time as large a surface as possible.Furthermore,a thick and solid electrode manufactured in one piece isliable to be broken during the process of electrolysis, whereby it isrendered entirely useless, and even detrimental to the operation. Myelectrodes are manufactured with a view to minimize this defeet. Forthis purpose I form the poles or electrodes of several carbon pieces ofany convenient shape and of comparatively small sectionalarea, which canreadily be produced of uniform density and strength throughout. Thesesmall carbon'pieces are united together, so as to form a body whichshallbehave,as'far as electrical conductivity is concerned, as nearly aspossible as one homogeneous mass, and by its corrugated form willpresent a larger surface than one solid block would.

The probability of all of these rods breaking at one and the same timeis very remote, and should a single rod break the current would still beconveyed through the remainder, and after the operation the broken rodcould easily be replaced. If necessary, a number of such bundles couldbe used as one electrode. For the purpose of making them act throughoutthe entire mass as one homogeneous piece, a thorough contact must beestablished between the individual pieces themselves, as the simplesuperposition is insufficient.

In the drawings, Figure 1 includes a lon gitudinal and a transversesection of the improved electrode having metallic caps at its ends. Fig.2 includes a longitudinal and a transverse section of this improvedelectrode having carbon caps at its ends. Fig. 3 includes a longitudinaland a transverse section of this improved electrode having a carbonfilling in the interstices between its separate carbon rods. Fig. 4includes an end and a side elevation of a rotary drum having theseimproved electrodes mounted therein.

Similar letters of reference indicate corresponding parts in thedifferent figures.

The electrode A comprises a series of separate carbon rods, a, bundledtogether and provided with a cap, I). The rods abefore being bundled arepreferably provided with a copper coating at their ends, depositedthereon electrolytically or otherwise, which coating assists inestablishing a good metallic connection when they are united together.The so ooppered carbon rods a are then assembled together in the form ofa bundle, and copper is then deposited upon the ends of the bundle,which unites with the copper on the ends of of carbon instead of metal,if preferred. The

interstices between the rods of the bundle may be filled in with abinding carbon material and baked therein, thereby practicallyconstituting a solid composite carbon electrode. This carbon material iscomposed of a carbon paste made according to any of the preferredformulas for carbon paste for making battery-carbons. The intersticesare filled with this paste and the'bundle is subjected to a red orbaking heat. These compound electrodes may be mounted between two disks,d d, forminga rotary drum for use in electrolytical apparatus.

In electrolytical decomposition care'must be taken that the solutiondoes not come in contact with the metal on the carbon either directly orby capillary action, as it would be liable to be dissolved or affected.Even when the metallic ends of the carbons are placed.

outside of the solution the capillary action is liable to attractsuflicient solution to affect the metal and destroy the contact betweenit and the carbons. To prevent this I immerse the ,rods or bundle atthose points where this capillary action would have such a detrimentaleffect upon the metallic covering, before being coppered or coated withmetal, in a suitable insulating material, by means of whichthe'interstices at the end are also filled, or these may be filledseparately.

I amawarethat separate carbon rods have heretoforebeen bundled together,and that they 40 have also been mounted apart from each other inmetallic rings 5 but in neither case were they united as hereindescribed.

I am also aware that it is notnew, broadly, to electroplate theconnections between the carbon and the leading-in Wires of anincandescent electric lamp.

Having fully described my invention, what I desire to claim and secureby Letters Patent 1s 1.- An electrode composed of a number of carbonrods or pieces and a filling between them of carbon material bakedtherein, the ends of said rods being insulated, substantially asdescribed. 5 5

2. An electrode consisting of a number of single carbon rods arranged inthe form of a bundle, the interstices of which are filled wholly orpartly with binding and conductive carbon material, as described, andfor the pur- 6o pose specified.

3. An electrode composed of a number of carbon rods or pieces, and afilling between them of carbon material baked therein, the ends of saidrods being insulated andv coppered, substantially as described.

4.. An electrode consisting of a number of carbon rods bundled together,withinterstices filled with carbon material, and the ends of which arecoppered, as described, and for the purpose specified.

HENRY LIEPMANN.

Witnesses:

HERBERT J. ALLIsoN, J NO. DEAN.

